I am sure that they expected Zappe to be the guy for the #2 position all offseason and discovered that wasn't going to work out as camp went on. However, during camp, most QBs are already spoken for as all teams need their camp arms. They were pretty much forced to wait until cutdowns to start making calls, but then at that point, you're talking about getting a veteran in here this week to start learning the playbook immediately and probably not being knowing much of it by Week 1, or just waiting one more week to make it easier on the cap. I am sure Bill probably looks at the Eagles game and knows he needs Mac if he wants to win that one. If Mac gets hurt, victory becomes a lot less likely, and I doubt Bill thinks that a veteran who just got to town would substantially boost that chance over Zappe for that specific game.